Health-related behaviors and weight-related outcomes within sibling pairs: A systematic review

Background: Siblings reciprocally contribute to mutual social and physical development. The aim of this review was to examine the health-related behaviors and weight-related outcomes within child-sibling pairs and to determine how these factors vary by sibling composition.Methods: Following the PRISMA guidelines, a systematic review of studies published since 2000 obtained from MEDLINE, CINAHL, PubMed, Cochrane Reviews, Web of Science, PsycINFO, Health and Wellness, and Science Direct was performed. The eligibility criteria for inclusion were: 1) peer-reviewed and published in English; 2) included children ages 2 to 20 and their siblings; and 3) explored health-related behaviors (i.e., diet) and/or weight-related outcomes (i.e., body weight) within child-sibling dyads.Results: A total of 13 studies were included in the review. The study findings are summarized according to three major themes: 1) sibling concordance in health-related behaviors and weight-related outcomes, 2) differences in health-related behaviors within weight-concordant/weight-discordant sibling dyads, and 3) influence of sibling composition on health-related behaviors and weight-related outcomes. Conclusions: Family-based interventions for childhood obesity may benefit from including siblings as key family members in promoting children's health-related behaviors and preventing excessive weight gain. Future studies should explore variable sibling dynamics (e.g., adoptive siblings) in more culturally/racially diverse families to further explore the role of a sibling in a child's health. Implications to practice: The findings of this study may help healthcare providers in developing effective family -based obesity interventions for families with more than one child in their household.